In the paper industry, equipment for the packaging of paper stacks can have, associated therewith, a so-called transfer device or apparatus having a transfer table which can be extendable and retractable and over which a belt can pass.
The apparatus has a multiplicity of deflection rollers around which the belt can pass. The belt passes onto the upper surface of the transfer table, around a front deflection roller and then around the multiplicity of deflection rollers mentioned earlier along a return path. At least one of these deflection rollers is constituted as a compensating roller and can shift in position to vary the length of a belt loop as the transfer table is extended or retracted.
It will be understood that at least one of the deflection rollers can be driven so that the belt can be displaced along the table to transfer a stack of paper thereon.
In the paper industry, such transfer apparatus may be used to take up an unpackaged paper stack at one end and to feed this stack into the wrapping mechanism at the other end.
Because the transfer device must accommodate to various formats of the paper stack, i.e. different dimensions of a paper sheet stack to be accommodated thereby and hence the degree of shift of a stack for the packaging operation, the transfer table may have to be extended or retracted during format changes. In any case the belt will displace the paper stack along the portion of the transport path defined by this transfer table.
In the transfer apparatus in current use for this purpose, the transfer table has a telescoping construction in which one part of the table telescopingly receives another part thereof and the transfer table as a whole is telescopingly extendable and retractable. As a result, the extension and retraction are limited by the telescoping construction.
For example, it is not possible to contract the transfer table, because of the requirement of a telescoping construction, to a comparatively short transfer length as may be required in some cases. Furthermore, the transition between portions of a telescoping transfer table may be stepped rather than smooth, causing a stepped movement of the stack as well.
The stepped movement and construction has been found to be detrimental to the operation of the equipment.